Functional Safety Engineer (TÜV Rheinland) Safety Instrumented Systems

Day one — Functional Safety and lifecycle management

Introduction to Functional Safety

Understand why safety systems fail and how the standards address the engineering and organisational causes.

• Industrial incidents and lessons from the history of process safety; the meaning of safety and the context of legal and regulatory requirements.
• Layers of protection; Safety Instrumented Systems (SIS), Safety Instrumented Functions (SIFs) and Safety Integrity Levels (SILs).
• Problems and failure mechanisms in safety systems; the purpose, scope and relationship of IEC 61508 and IEC 61511.

Functional Safety Management

Connect lifecycle requirements with the management arrangements needed to carry them out.

• The safety lifecycle, competence and allocated responsibilities; risk evaluation and management.
• Safety planning, implementation and monitoring; Functional Safety Assessments, audits and configuration management.

Safety lifecycle planning and verification

Review how lifecycle inputs, outputs and acceptance evidence are planned and controlled.

• Lifecycle structure and planning; the Functional Safety Management system; verification and validation planning; the role of the Safety Requirements Specification (SRS).
• Verification planning and testing; application-program verification and the documentation supporting each lifecycle activity.

Day two — Hazard assessment and safety requirements

Process hazard and risk assessment

Evaluate process risk and understand the basis for selecting and documenting risk reduction.

• Hazards, consequences and risk; tolerable risk, ALARP and risk management.
• Hazard identification methods including FMEA, fault tree analysis and HAZOP; analysis using event trees, dispersion modelling and bowtie techniques.
• Risk matrices and risk graphs; selecting and applying risk reduction methods.
• The interface with security risk assessment, including digital system mapping, security levels, security assurance concepts and IEC 62443 foundational requirements.

Allocation of safety functions to protection layers

Work through the reasoning behind protection-layer claims and the required integrity of a SIF.

• Layer of Protection Analysis (LOPA), Independent Protection Layer (IPL) characteristics and a worked LOPA example.
• Strengths and limitations of LOPA, relevant CCPS guidance, SIF operating modes and safety integrity requirements.

Safety Requirements Specification

Translate assessment outputs into requirements that engineers, operators and maintenance teams can use.

• General SRS requirements and the information needed to describe each SIF.
• Mean Time to Restoration (MTTR), Mean Repair Time (MRT) and their implications for the safety function.
• Application-program safety requirements and their relationship to the overall SRS.

Day three — Engineering and the operational lifecycle

SIS design and engineering

Review the evidence needed to support a SIL claim and the practical implications of hardware decisions.

• General hardware requirements, hardware concepts and the use of IEC 61508 safety manuals.
• SIF operating modes; safety availability and process availability; Hardware Fault Tolerance (HFT).
• Diagnostics and proof testing; Safe Failure Fraction (SFF); architectural constraints and the applicable Route 1H and Route 2H provisions.
• Selection of devices and field instruments; maintenance and testing requirements; quantification of random hardware failures.
• The three elements behind a SIL claim: systematic integrity, architectural constraints and the required probability of dangerous failure.

Application-program development

Follow a controlled development process from requirements to tested implementation.

• General application-program requirements, design and implementation.
• The V-model, lifecycle documentation, verification and testing; development methodologies and tools.

Installation, commissioning and validation

Understand how the installed SIS is shown to meet its specified requirements.

• Installation planning and records; commissioning activities, procedures and techniques.
• Factory Acceptance Testing (FAT), Site Acceptance Testing (SAT) and their contribution to validation against the SRS.

Operation and maintenance

Maintain the assumptions and integrity established during engineering.

• Operation and maintenance planning and procedures; operator and maintenance training.
• Bypasses and maintenance override switches; a proof-test procedure for each SIF.

Modification and decommissioning

Control lifecycle changes and the risks introduced when safety functions are altered or removed.

• Modification objectives and required inputs; distinguishing maintenance changes from modifications.
• Activities before, during and after modification; the Functional Safety Assessment required before starting the modification.
• Decommissioning procedures, analysis and authorisation, including the requirements and risks associated with affected SIFs.

Practical exercises

Industrial examples, incident videos, discussion and exercises connect the standards with engineering practice. Exercises include failure classification, FMEA, fault tree analysis, HAZOP and hazard analysis, SIL determination using risk matrices and risk graphs, safety versus process availability, HFT and comparison of SIF design and device options. Questions and answers are encouraged throughout the course.

Duration and delivery

Classroom delivery comprises three consecutive training days and a four-hour examination on the morning of day four, normally described as a 3.5 day course. Live online delivery normally follows a 4.5 day Monday-to-Friday format, with three training days, a review and self-study period, and the online examination. Check the selected event for its approved delivery schedule, dates and time zone.

Course materials are in English. Spoken delivery may be English, Dutch or Hindi, depending on the location and trainer; the language is stated for each event.

Materials and preparation

Materials comprise two handout volumes with slides, exercises, homework and abbreviations, plus the GMI SIL Manual, fourth edition. Paper or electronic formats depend on delivery method and availability. Check the event for the supplied format.

Recommended preparation is IEC 61511 and SRS chapters of the GMI SIL Manual. Allow time each evening to review the homework and prepare for the next day and examination.